1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * X.25 Packet Layer release 002
4 *
5 * This is ALPHA test software. This code may break your machine,
6 * randomly fail to work with new releases, misbehave and/or generally
7 * screw up. It might even work.
8 *
9 * This code REQUIRES 2.1.15 or higher
10 *
11 * History
12 * X.25 001 Jonathan Naylor Started coding.
13 */
14
15 #include <linux/if_arp.h>
16 #include <linux/init.h>
17 #include <linux/slab.h>
18 #include <net/x25.h>
19
20 LIST_HEAD(x25_route_list);
21 DEFINE_RWLOCK(x25_route_list_lock);
22
23 /*
24 * Add a new route.
25 */
26 static int x25_add_route(struct x25_address *address, unsigned int sigdigits,
27 struct net_device *dev)
28 {
29 struct x25_route *rt;
30 int rc = -EINVAL;
31
32 write_lock_bh(&x25_route_list_lock);
33
34 list_for_each_entry(rt, &x25_route_list, node) {
35 if (!memcmp(&rt->address, address, sigdigits) &&
36 rt->sigdigits == sigdigits)
37 goto out;
38 }
39
40 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
41 rc = -ENOMEM;
42 if (!rt)
43 goto out;
44
45 strcpy(rt->address.x25_addr, "000000000000000");
46 memcpy(rt->address.x25_addr, address->x25_addr, sigdigits);
47
48 rt->sigdigits = sigdigits;
49 rt->dev = dev;
50 refcount_set(&rt->refcnt, 1);
51
52 list_add(&rt->node, &x25_route_list);
53 rc = 0;
54 out:
55 write_unlock_bh(&x25_route_list_lock);
56 return rc;
57 }
58
59 /**
60 * __x25_remove_route - remove route from x25_route_list
61 * @rt: route to remove
62 *
63 * Remove route from x25_route_list. If it was there.
64 * Caller must hold x25_route_list_lock.
65 */
66 static void __x25_remove_route(struct x25_route *rt)
67 {
68 if (rt->node.next) {
69 list_del(&rt->node);
70 x25_route_put(rt);
71 }
72 }
73
74 static int x25_del_route(struct x25_address *address, unsigned int sigdigits,
75 struct net_device *dev)
76 {
77 struct x25_route *rt;
78 int rc = -EINVAL;
79
80 write_lock_bh(&x25_route_list_lock);
81
82 list_for_each_entry(rt, &x25_route_list, node) {
83 if (!memcmp(&rt->address, address, sigdigits) &&
84 rt->sigdigits == sigdigits && rt->dev == dev) {
85 __x25_remove_route(rt);
86 rc = 0;
87 break;
88 }
89 }
90
91 write_unlock_bh(&x25_route_list_lock);
92 return rc;
93 }
94
95 /*
96 * A device has been removed, remove its routes.
97 */
98 void x25_route_device_down(struct net_device *dev)
99 {
100 struct x25_route *rt;
101 struct list_head *entry, *tmp;
102
103 write_lock_bh(&x25_route_list_lock);
104
105 list_for_each_safe(entry, tmp, &x25_route_list) {
106 rt = list_entry(entry, struct x25_route, node);
107
108 if (rt->dev == dev)
109 __x25_remove_route(rt);
110 }
111 write_unlock_bh(&x25_route_list_lock);
112 }
113
114 /*
115 * Check that the device given is a valid X.25 interface that is "up".
116 */
117 struct net_device *x25_dev_get(char *devname)
118 {
119 struct net_device *dev = dev_get_by_name(&init_net, devname);
120
121 if (dev && (!(dev->flags & IFF_UP) || dev->type != ARPHRD_X25)) {
122 dev_put(dev);
123 dev = NULL;
124 }
125
126 return dev;
127 }
128
129 /**
130 * x25_get_route - Find a route given an X.25 address.
131 * @addr: - address to find a route for
132 *
133 * Find a route given an X.25 address.
134 */
135 struct x25_route *x25_get_route(struct x25_address *addr)
136 {
137 struct x25_route *rt, *use = NULL;
138
139 read_lock_bh(&x25_route_list_lock);
140
141 list_for_each_entry(rt, &x25_route_list, node) {
142 if (!memcmp(&rt->address, addr, rt->sigdigits)) {
143 if (!use)
144 use = rt;
145 else if (rt->sigdigits > use->sigdigits)
146 use = rt;
147 }
148 }
149
150 if (use)
151 x25_route_hold(use);
152
153 read_unlock_bh(&x25_route_list_lock);
154 return use;
155 }
156
157 /*
158 * Handle the ioctls that control the routing functions.
159 */
160 int x25_route_ioctl(unsigned int cmd, void __user *arg)
161 {
162 struct x25_route_struct rt;
163 struct net_device *dev;
164 int rc = -EINVAL;
165
166 if (cmd != SIOCADDRT && cmd != SIOCDELRT)
167 goto out;
168
169 rc = -EFAULT;
170 if (copy_from_user(&rt, arg, sizeof(rt)))
171 goto out;
172
173 rc = -EINVAL;
174 if (rt.sigdigits > 15)
175 goto out;
176
177 dev = x25_dev_get(rt.device);
178 if (!dev)
179 goto out;
180
181 if (cmd == SIOCADDRT)
182 rc = x25_add_route(&rt.address, rt.sigdigits, dev);
183 else
184 rc = x25_del_route(&rt.address, rt.sigdigits, dev);
185 dev_put(dev);
186 out:
187 return rc;
188 }
189
190 /*
191 * Release all memory associated with X.25 routing structures.
192 */
193 void __exit x25_route_free(void)
194 {
195 struct x25_route *rt;
196 struct list_head *entry, *tmp;
197
198 write_lock_bh(&x25_route_list_lock);
199 list_for_each_safe(entry, tmp, &x25_route_list) {
200 rt = list_entry(entry, struct x25_route, node);
201 __x25_remove_route(rt);
202 }
203 write_unlock_bh(&x25_route_list_lock);
204 }
205
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.